Surgical Management of Symptomatic Lumbar, Sacral, and Lumbosacral Plexus Tumors: a Peripheral Nerve Unit Experience.

OBJECTIVE: Data concerning the surgical treatment of lumbosacral plexus tumors (LSPTs) is scarce. This study aims to present our experience with a series of 19 patients surgically treated for symptomatic LSPTs at our institution. METHODS: This is a retrospective study of 19 patients surgically treated for symptomatic LSPTs from 2011 to 2019. Clinical data were retrieved from medical records and consisted of age, gender, clinical presentation, location of the lesion, surgical approach, final histopathologic diagnosis, follow-up time, outcomes, and complications. RESULTS: Nineteen surgical procedures were conducted. Thirteen patients were female and six, male. The median age of patients was 45 years (range 20 to 63 years). No patients harbored genetic syndromes. Surgical treatment appears to be correlated to the reduction of pain in patients with peripheral nerve sheath tumors (PNSTs), as assessed by visual analog scale (VAS). Sixteen patients did not present with new-onset deficits during follow-up (84.2%), two of whom recovered from their preoperative deficit. Four patients presented with postoperative weakness. The histopathological diagnoses were 11 schwannomas, four neurofibromas, three metastases, and one lymphoma. CONCLUSIONS: LSPTs are rare. When surgical treatment is indicated, it usually requires multidisciplinary management. Surgery appears to be effective concerning the reduction of pain in PNSTs and may also recover neurological deficits. Iatrogenic neurological deficits are an evident risk, such that intraoperative multimodal monitoring should always be performed if available. In lesions involving the sacral plexus, we found it to be indispensable.

Anatomical feasibility of peripheral nerve transfer to reestablish external anal sphincter control - cadaveric study.

PURPOSE: Motor deficits affecting anal sphincter control can severely impair quality of life. Peripheral nerve transfer has been proposed as an option to reestablish anal sphincter motor function. We assessed, in human cadavers, the anatomical feasibility of nerve transfer from a motor branch of the tibialis portion of the sciatic nerve to two distinct points on pudendal nerve (PN), through transgluteal access, as a potential approach to reestablish anal sphincter function. METHODS: We dissected 24 formalinized specimens of the gluteal region and posterior proximal third of the thigh. We characterized the motor fascicle (donor nerve) from the sciatic nerve to the long head of the biceps femoris muscle and the PN (recipient nerve), and measured nerve lengths required for direct coaptation from the donor nerve to the recipient in both the gluteal region (proximal) and perineal cavity (distal). RESULTS: We identified three anatomical variations of the donor nerve as well as three distinct branching patterns of the recipient nerve from the piriformis muscle to the pudendal canal region. Donor nerve lengths (proximal and distal) were satisfactory for direct coaptation in all cases. CONCLUSIONS: Transfer of a motor fascicle of the sciatic nerve to the PN is anatomically feasible without nerve grafts. Donor nerve length was sufficient and donor nerve functionally compatible (motor). Anatomical variations in the PN could also be accommodated.

Nondiscogenic Sciatica: What Clinical Examination and Imaging Can Tell Us?

OBJECTIVE: Lesions affecting the sciatic nerve (SN) can mimic lumbar radiculopathy. In patients presenting with sciatica, approximately 10% have a nondiscogenic etiology. Through neurological examination and imaging, it may be possible to confirm nondiscogenic sciatica (NDS). This study aims to present a series of 6 patients with infragluteal NDS, highlighting clinical and imaging aspects that may suggest this diagnosis. METHODS: This is a retrospective study of 6 patients treated for NDS from 2010 to 2018. The mean and median ages were 41.2 and 38.5 years, respectively, with all patients female. RESULTS: All patients presented with sciatic pain, tenderness to deep infragluteal palpation, and a positive Tinel's sign related to the SN. Four patients were referred for surgical treatment, whereas 1 underwent pharmacological therapy and 1 underwent incisional biopsy and radiotherapy. In our series, 6 different causes for NDS were diagnosed: 1 nontumorous cause: extrauterine endometriosis and 5 tumors: metastasis from rectal adenocarcinoma, low-grade sarcoma, schwannoma, high-grade sarcoma, and myxoma. CONCLUSIONS: Differentiating between discogenic and NDS can be challenging for clinicians. When patients present with sciatic pain, a Tinel's sign related to the SN elicited at the deep infragluteal region, tenderness to deep infragluteal palpation, occasionally with an SN motor deficit and imaging findings of the lumbar spine that do not justify a discogenic source, the cause should be considered nondiscogenic and they should be scheduled for magnetic resonance imaging of the gluteal and pelvic region.

Pediatric peripheral nerve tumors: clinical and surgical aspects.

PURPOSE: Pediatric peripheral nerve tumors (PNTs) are rare. Most are related to neurofibromatosis type 1 (NF1) with the potential for malignancy. An ongoing debate occurs about the best approach to such patients. This study describes a cohort of pediatric patients with PNTs and discusses clinical characteristics and surgical treatment. METHODS: We retrospectively reviewed the charts of seven pediatric patients with eight PNTs surgically treated from 2007 to 2018. Information concerning patient demographics, clinical presentation, PNTs characteristics, treatment choice, and outcome were recorded. RESULTS: All children presented with intense pain and a palpable mass. Three of the eight tumors were associated with a neurological deficit. Among the four patients with NF1, two had a neurofibroma and two a malignant peripheral nerve sheath tumor (MPNST). Histologically, three of the lesions were a benign peripheral nerve sheath tumor (BPNST), three a MPNST, and one each a desmoid tumor and Ewing's sarcoma. Two of the eight tumors underwent partial tumor excision and six gross total excisions. CONCLUSIONS: Intense pain at rest, day, and/or night, preventing normal activities; a palpable, hard, immobile mass; an intense Tinel's sign related to the lump; clinical evidence of NF1; and high-speed growth of a tumor in the trajectory of the nerve or plexus should alert the clinician to the potential for malignancy. Preoperative biopsy is not indicated when clinical and imaging findings suggest a benign tumor. The surgical management of PNTs must be to achieve total resection, including wide margins with malignant tumors, though this is not always possible.

An anatomical study of so-called fibrous bands around the ulnar nerve distal to the cubital tunnel.

BACKGROUND: Fibrous bands (FB) are structures that cross the ulnar nerve (UN), distal to the cubital tunnel (CT). In surgical decompression of the UN in the elbow region, by endoscopy, these FB significantly impact UN visibility. The aim of the current study was to characterize the anatomical characteristics of these FB distal to the CT. METHODOLOGY: Eighteen formalinized upper limbs were dissected, nine right and nine left, within the Department of Anatomy of the Federal University of the State of Rio de Janeiro (UNIRIO). The dissections were performed with micro techniques, under a magnifying glass and a microscope. Classical UN exposure was established in the elbow region. RESULTS: Of the 18 upper limbs studied, 50% lacked any FB. When present, both the number and location of the FB varied, as near to the cubital tunnel as 3 cm past the UN's entrance into the tunnel, and as far away as almost 11 cm distal to it. Overall, there were no FB on either the left or right side in three cadavers (33.3%), FB on both the left and right side in three, and FB only on the left in three, meaning that FB were twice as common in left limbs (n = 6) as on the right (n = 3). CONCLUSIONS: Our study identified FB in 50% of the dissected limbs, all within 3-11 cm of the CT, though their number and location varied. Further studies are necessary to describe FB variations associated with compressive neuropathies of the UN distal to the CT.